The U2AF1 antibody is a crucial tool in studying the U2 small nuclear RNA auxiliary factor 1 (U2AF1), a component of the U2 spliceosome complex essential for pre-mRNA splicing. U2AF1 recognizes the AG dinucleotide at the 3' splice site during spliceosome assembly, ensuring accurate intron removal and exon joining. Mutations in U2AF1. particularly at hotspots like S34F/Y or Q157R/P, are recurrently observed in myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and other cancers. These mutations disrupt normal splicing, leading to aberrant mRNA isoforms that may drive oncogenesis. Antibodies targeting U2AF1 enable detection of its expression, localization, and mutant variants in research and diagnostics. They are widely used in techniques like Western blotting, immunohistochemistry, and immunofluorescence to explore U2AF1's role in splicing regulation, disease mechanisms, and therapeutic targeting. Studies using U2AF1 antibodies have revealed its involvement in splicing dysregulation linked to cellular proliferation, differentiation defects, and genomic instability. Additionally, these antibodies aid in evaluating U2AF1 as a potential biomarker for clonal hematopoiesis or prognosis in hematologic malignancies. Ongoing research leverages U2AF1 antibodies to dissect mutation-specific effects on splicing and to develop precision therapies for U2AF1-mutant cancers.